In some semiconductor manufacturing processes, wafer processing chambers or reactors are used to process wafers from which integrated circuits are made. During the manufacturing process, a wafer is placed on a wafer holder (or susceptor). After the wafer has been placed on the wafer holder, it is placed in a processing chamber or reactor where a high temperature process is performed using lamp modules. The lamp modules may be located in different zones over and under the wafer holder to heat the wafer holder and the wafer such that wafer processing may be performed on the wafer.
For example, wafer processing such as chemical vapor deposition (CVD), using lamp modules, may be performed to deposit or epitaxially (epi) grow film layers on the wafer. As the CVD process is carried out, the amount of film deposited on the wafer may vary as a function of the temperature profile of the wafer. The temperature profile across the wafer may not be uniform for a variety of reasons. For example, the temperature profile may not be uniform across the wafer because various lamp module's power output may deteriorate over time, thereby causing temperature differences between various areas of the wafer. As such, the uneven temperature profile results in uneven/varying film thickness and uniformity that ultimately adversely affects the performance of the integrated circuit made from the wafer. Temperature profile uniformity can also be important for other wafer processing such as rapid thermal processing (RTP), annealing, doping, etching, and other processes. Accordingly, there is a need for an improved method and device to more uniformly control wafer temperature during wafer processing.